Synergism of ABI and HES for Atmospheric and Cloud Products

The Advanced Baseline Imager (ABI) and the Hyperspectral Environmental Suite (HES) on GOES-R and beyond will enable improved monitoring of the distribution and evolution of atmospheric thermodynamics and clouds. The HES will be able to provide hourly atmospheric soundings with spatial resolution of 4 ~ 10 km with high accuracy. However, the presence of clouds affects the sounding retrieval and needs to be dealt with properly. The ABI is able to provide, at high spatial resolution (0.5 ~ 2 km), a cloud mask, surface and cloud types, cloud phase mask etc, cloud top pressure (CTP), cloud particle size (CPS), and cloud optical thickness (COT). The combined ABI/HES system offers the opportunity for new or better atmospheric and cloud products. For example, collocated ABI can (1) provide HES sub-pixel cloud characterization (mask, amount, phase, layer information, etc.); (2) be used for HES cloud-clearing for partly cloudy HES footprints; and (3) provide background information for a variational retrieval of cloud properties with HES cloudy radiances. The Moderate-Resolution Imaging Spectroradiometer (MODIS) and the Atmospheric Infrared Sounder (AIRS) measurements from the Earth Observing System's (EOS) Aqua satellite provide the opportunity to study the synergistic use of advanced imager and sounder measurements. The combined MODIS and AIRS data for various scenes are analyzed to study the utility of synergistic use of ABI products and HES radiances for better retrieving atmospheric soundings and cloud properties. In order to derive sounding from combined ABI and HES radiances under HES partly cloudy footprint where no microwave-sounding data is available, an optimal cloud-removal or cloud-clearing algorithm is developed. The bias and the standard deviation between the convoluted cloud-cleared brightness temperatures (BTs) and MODIS clear BT observations is less than 0.25 K and 0.5 K, respectively, over both water and land for most MODIS IR spectral bands, reveals the potential operational use of imager/sounder for cloud-clearing. The impacts of the GOES-R system design and scan scenarios on the ABI/HES synergism are also studied.